1. Field of the Invention
The present invention relates to a method and apparatus for sweeping a target with a range-finder such as radar, and using the return signals to identify characteristic features of the target. The invention may be used in the compilation of target recognition data for known targets, in the identification in real time of a particular target, or in the discrimination in real time between a number of possible targets. The invention has particular application in high resolution radar range finding.
2. Description of the Prior Art
As disclosed in our copending UK patent application no. 8615683, return signals from a high resolution radar may be plotted as dots, whose size is proportional to return signal amplitude, on a graph of range against the angle between the target and the line between the target and the radar. From such a graph it is possible to connect the more significant dots to form curves which are characteristic of the target. In such a method, errors arise from the motion of the target during the accumulation of the range data. A target point, for example the funnel of a ship, might give rise to an irregular curve instead of a portion of a sine wave, making the recognition process more difficult.